Plant growth hormone compositions

ABSTRACT

A plant growth promoter composition is provided comprising: (a) not in excess of 20% by weight of one or more gibberellins; and (b) an essentially non-aqueous solvent system comprising: (i) 30 to 99% by weight of one or more lipophilic solvents; (ii) at least an equivalent molar amount to the gibberellins of one or more lipophilic alkaline coupling agents which enable the gibberellins to form a lipophilic solvent soluble complex; (iii) 1 to 50% by weight of one or more emulsifiers which blend with the lipophilic solvent(s) to form a homogeneous product and enable dispersion of the composition into water for application; and (iv) optionally, not in excess of 15% by weight of one or more viscosity reducing co-solvents.

FIELD OF THE INVENTION

This invention relates to plant growth hormone compositions. Moreparticularly, the present invention relates to gibberellin compositionsand a method of increasing the efficacy of gibberellins.

BACKGROUND OF THE INVENTION

In this specification, where a document, act or item of knowledge isreferred to or discussed, this reference or discussion is not anadmission that the document, act or item of knowledge or any combinationthereof was at the priority date:

(i) part of common general knowledge; or

(ii) known to be relevant to an attempt to solve any problem with whichthis specification is concerned.

The agricultural industry has found that the use of plant growthhormones can aid in the control of crop quality and thus the value ofthe harvest. Plant growth hormones evidence several effects includingthe ability to either stimulate or inhibit growth. There are five majorgroups of plant hormones: auxins, gibberellins, ethylene, cytokinins andabscisic acid. The more commonly used groups in agriculture at themoment are the auxins, gibberellins, ethylene and cytokinins.

The gibberellins, which include gibberellic acid or GA-3, areresponsible for promoting growth in most plants. They are, for example,known to cause growth in dwarf mutants so that they areindistinguishable from normal tall, non-mutant plants. Seed germinationcan be hastened by application of gibberellins. Some plants havedifferent juvenile and adult growth and gibberellins applied to a bud onadult growth will cause formation of juvenile growth. Application toplants which form rosettes before flowering will induce bolting andflowering. Gibberellins also stimulate pollen germination.Parthenocarpic fruit can be caused by gibberellins in some fruits suchas apples, currants, cucumbers, eggplants, mandarin oranges, almonds andpeaches.

Gibberellins are used commercially to increase fruit size and their setand cluster sizes. For example, application of gibberellins to grapes iswell known. It also induces a much looser appearance to the cluster ofgrapes. Other areas of known uses of gibberellins include delaying theripening of citrus fruit on trees, stimulating flowering of strawberriesand stimulating the partial digestion of starches in germinating barleyduring the process of brewing beer.

The gibberellins cannot be easily directly applied to a crop and requirea solvent system as a carrier for such applications. Further,gibberellins are slowly hydrolysed in aqueous solutions and thereforecannot be stored long term in aqueous solutions. Commercial solutionsare thus non-aqueous. Gibberellins are currently dissolved in alcoholsolutions, particularly methanol. Methanol is both flammable andpoisonous. The Dangerous Goods Authorities therefore demand that allproducts which contain methanol, including gibberellin solutions, bemarked as both flammable and poisonous and handled accordingly.

For application, the farmer dilutes the methanol gibberellin (usuallygibberellic acid) solution with water and then this is sprayed onto thecrop. Numerous applications of this gibberellin spray are necessary toachieve the desired effects. When used on grape vines, the firstapplications, typically two, are termed thinning sprays because theirtiming is designed to reduce the number of grapes per bunch. The laterapplications are used to increase the size of the grapes and are calledsizing sprays. It is recognised that whilst the gibberellin is‘taken-up’ through the foliage of the plant, the cuticle of the foliageis covered with a thin layer of wax which renders it hydrophobic anddifficult to permeate. As a result, the uptake by the foliage ofgibberellin in an aqueous solution is not efficient. This inefficiencyis further increased when the methanol and water have evaporated leavingthe gibberellin as a ‘deposit’ on the foliage. As gibberellins areexpensive, the farmer is always balancing the cost of such applicationsagainst the increase in the price of the fruit that may be achieved.

In relation to fruits (eg. grapes, citrus fruits and strawberries),their perceived quality and thus sale value is measured in part by thesize and colour of the fruit. A cost-effective method which would

increase the size of fruit;

achieve fruit maturity at an earlier date; and

eliminate any undesirable flammable/poisonous carrier would therefore beof value to the grape grower.

Accordingly, investigations have been carried out in an effort toachieve one or more of these goals.

SUMMARY OF THE INVENTION

It has been found that the lack of solubility of gibberellins inlipophilic solvents has been overcome through the use of certainlipophilic solvent systems. This is of interest because they are notflammable like the lower alcohols such as methanol.

According to the invention, a plant growth promoter composition isprovided comprising:

(a) not in excess of 20% by weight of one or more gibberellins; and

(b) an essentially non-aqueous solvent system comprising:

(i) 30 to 99% by weight of one or more lipophilic solvents;

(ii) at least an equivalent molar amount to the gibberellin(s) of one ormore lipophilic alkaline coupling agents which enable the gibberellin(s)to form a lipophilic solvent soluble complex;

(iii) 1 to 50% by weight of one or more emulsifiers which blend with thelipophilic solvent(s) to form a homogeneous product and enabledispersion of the composition into water for application; and

(iv) optionally, not in excess of 15% by weight of one or more viscosityreducing co-solvents.

It was further found that when gibberellins are used with this solventsystem, the growth promoting activity of gibberellins in fruit, and inparticular grapes, is enhanced. In particular, use of the solvent systemproduces grape berries of earlier maturity, larger dimensions and abetter appearance showing less russetting (pitting) and lessdiscoloration.

According to a second aspect of the invention there is provided a methodfor enhancing the efficacy of at least one gibberellin acting as a plantgrowth promoter comprising the step of incorporating gibberellins intoplant growth promoter compositions comprising:

(a) an essentially non-aqueous solvent system comprising:

(i) 30 to 99% by weight of the total composition of one or morelipophilic solvents;

(ii) at least an equivalent molar amount to the gibberellin(s) of one ormore lipophilic alkaline coupling agents which enable the gibberellin(s)to form a lipophilic solvent soluble complex;

(iii) 1 to 50% by weight of the total composition of one or moreemulsifiers which blend with the lipophilic solvent(s) to form ahomogeneous product and enable dispersion of the composition into waterfor application; and

(iv) optionally, not in excess of 15% by weight of the total compositionof one or more viscosity reducing co-solvents.

The gibberellins may be any member of the gibberellin family known tothose skilled in the art. Preferably, the gibberellin is gibberellicacid (Gibberellin A-3). Preferably, the amount of gibberellins is in therange of 1 to 15% by weight. More preferably, the amount of gibberellinsis in the range of 4 to 10% by weight. The current commercial productscontain either 4 or 10% by weight gibberellins.

The lipophilic solvents which can be used include mineral oils, waxesand other petroleum fractions; vegetable and animal oils, fats and waxesand their simple esters; and fatty alcohols and/or synthetic branchedchain alcohols and their esters. Preferably, the amount of lipophilicsolvent is in the range of 40 to 80% by weight of the total composition.

Preferably, the lipophilic solvents are esters of vegetable oils, inparticular, one or more alkyl esters of fatty acids, such as ethyloleate. There are innumerable variations of the esters of vegetable oilssince the alkyl esters of fatty acids may be produced from thecombination of any one or more of the lower alcohols whilst the fattyacid moiety can be derived from the natural oils and fats such as lard,tallow and vegetable oils or from specific blends produced by fatty acidmanufacturers or from fatty acids produced by synthetic means or theirblends. Readily available commercial vegetable oils such as canola,corn, sunflower and soyabean oils are also sources for fatty acids.

Typically, the lipophilic alkaline coupling agents are selected from thefollowing lipophilic solvent soluble bases:

(a) quaternary ammonium hydroxides, overbased phenates, overbasedsulphonates;

(b) aromatic, arylalkyl, alkylaryl and polycyclic amines; and

(c) fatty amines and fatty imidazolines.

A suitable commercially available lipophilic alkaline coupling agent isdimethyl cocoamine. Preferably, the lipophilic alkaline coupling agentis a mixture of dimethyl cocoamine and oleylamine. Preferably, theamount of lipophilic alkaline coupling agent used is a molar excess tothe amount of gibberellins used. Typically, the amount of lipophilicalkaline coupling agent is in 30% molar excess to the amount ofgibberellins.

The properties of the emulsifier system which comprises one or moreemulsifiers, will be well known to those skilled in the art and it isrecognised that there are a multitude of suitable combinations. Thoseskilled in the art will note that emulsifiers of certain types maydisturb the lipophilic solvent soluble complex, eg acids or anionics,and that these emulsifiers should be avoided. The emulsifier system willbe easily blended with the lipophilic solvents to furnish a homogeneousproduct and to enable dispersion, into water for application. Familiesof emulsifiers known to provide suitable emulsification of suchlipophilic solvents include sorbitan esters and ethoxylates, alcoholethoxylates, fatty acid ethoxylates (PEG esters), difatty alkylimidazoline derivatives and fatty betaines. It is recognised that othersurfactant types either alone or in combinations may also providesuitable emulsification. Preferably, the amount of emulsifiers used isin the range from 3 to 20% by weight of the total composition.

Viscosity reducing co-solvents will be known to those skilled in the artand include simple alcohols and monoalkyl ethers. If a high flash pointis to be maintained, the viscosity reducing co-solvent should be aglycol, diglycol or diglycol ether.

EXAMPLES

The invention will now be further illustrated with reference to thefollowing non-limiting examples.

The examples use the following components.

AT 1214 Dimethyl cocoamine ex Procter & Gamble, U.S.A. Butyl DiglysolvDiethylene glycol mono butyl ether ex Huntsman, Australia Butyl GlysolvEthylene glycol mono butyl ether ex Huntsman, Australia. Ecoteric T-80Sorbitan monooleate 20 moles EO ex Huntsman, Australia Esterol 123 80%ethyl oleate and 20% methyl oleate ex Victorian Chemicals, AustraliaEsterol 244 PEG 400 dioleate ex Victorian Chemicals, Australia EthanolAnhydrous industrial methylated spirits SGF3 ex CSR, Australia EthylDiglysolv Diethylene glycol mono ethyl ether ex Huntsman, Australia. GA4/7 mixture of two gibberellins of 96% purity ex Agtrol USA Gibberellicacid 90% technical grade Gibberellin A-3 powder ex Krishi Rasayan, Indiaor Agtrol, SUA Glysolv DPM Dipropylene glycol mono methyl ether exHuntsman, Australia ProGibb 4 4% Gibberellin A-3 in methanol ex AbbottLabs, U.S.A. ProGibb 10 10% Gibberellin A-3 in methanol ex Abbott Labs,U.S.A. NORAM-O Oleylamine; 9-octadecen-l-amine, (Z) ex Elf Atochem,France X-77 Alcohol ethoxylate ex Aventis, Australia

Example 1

In this example, a homogeneous composition of Gibberellin A-3 in alipophilic solvent was developed.

A solvent system was first prepared as follows.

Solvent system A Component Weight (g) Ecoteric T-80  63 Esterol 123 702Esterol 244 135 Water  5

This mixture was stirred until it cleared.

A series of compositions were prepared with 10%, 3% and 1%concentrations of Gibberellin A-3. The Gibberellin A-3 powder wasdispersed in the solvent system and then the other components added. Themixture was then stirred for 1-2 hours until clear.

Sample with 10% Gibberellin A-3 Component Weight (g) Ethanol 6.0Gibberellic acid 23.5 NORAM-O 21.0 Solvent system A 157.5 Water 3.0

The mixture was stirred at 40° C. and ethanol added to produce a lessviscous product. Other non-flammable viscosity reducing co-solvents areused in later examples.

Sample with 3% Gibberellin A-3 Component Weight (g) Gibberellic acid16.0 NORAM-O 16.0 Solvent system A 454.0

Sample with 1% Gibberellin A-3 Component Weight (g) Gibberellic acid2.25 NORAM-O 2.75 Solvent system A 195.00

Example 2

In this example, the effect of a lipophilic solvent-based solvent systemon the efficacy of Gibberellin A-3 was investigated.

Composition Tested Components w/w Ecoteric T-80 29.0 Esterol 123 324.0Esterol 244 62.3 Gibberellic acid 54.0 NORAM-O 41.5 Water 6.2

This formulation was prepared by mixing the components in the aboveorder with stirring and warmed to 40° C. until clear.

Method

A field of grape vines at Irymple, Victoria, was divided into fourseparate plots. The sprays for sizing were applied at night, the firstwhen 50% of the bunches had reached 4-6 mm berry size with a repeatapplication three days later and a final application five days after thesecond. The treatments were applied at a spray rate of 1500 liters ofwater per acre. Each plot was treated with a different composition asdescribed below. The Control was the usual Gibberellin A-3 (ProGibb 10)in methanol solution. The other three plots tested the Experimentalcomposition at three different application rates.

Rate ml (per 100 litres of water) Control 33.0 Experiment 1 23.4(approximately 75% normal Gibberellin A-3 rate) Experiment 2 15.6(approximately 50% normal Gibberellin A-3 rate) Experiment 3  7.8(approximately 25% normal Gibberellin A-3 rate)

The grapes were harvested about two and half months later. Theevaluation was undertaken by an independent assessor from the MelbourneFruit Market 3 days after harvest.

Results

At the time of the harvest, the grapes from each plot were commerciallyacceptable and had no significant variation in colour. That is, eventhough less Gibberellin A-3 was used in Experiments 1, 2 and 3,equivalent results were obtained to the Control. Although of overallsimilar size, the grapes from Experiment 2 contained the greatestproportion of larger sized berries.

Conclusion

From the above results, it is evident that the efficacy of theGibberellin A-3 is superior when carried in the new lipophilicsolvent-based system than in methanol. Indeed, equivalent if not betterresults are evidenced from half as much Gibberellin A-3 as waspreviously used.

Example 3

Compositions tested Control untreated Treatment 1 ProGibb 4% Treatment2* 4% Gibberellin A-3 in lipophilic solvent-based solvent systemTreatment 3* 2% Gibberellin A-3 in lipophilic solvent-based solventsystem *Treatments 2 and 3 had the following compositions (w/w):

Component Treatment 2 Treatment 3 Ecoteric T-80 6.3 6.6 Esterol 123 70.974.2 Esterol 244 13.7 14.2 Gibberellic acid 4.4 2.2 NORAM-O 4.0 2.0Water 0.7 0.8

Method

The treatments were tested both for thinning and sizing purposes at afarm in California, USA. All thinning treatments were applied to provide8 g Gibberellin A-3 per acre (i.e. 200 g of Treatments 1 and 2, and 400g of Treatment 3 were used). The spray rate was 200 US-gallons per acreat the time when the bloom was approximately 80%. All sizing treatmentsused 32 g Gibberellin A-3 per acre, with 3 days between applications.

Results

During the trials the spreading characteristics of the invention'ssolvent system were superior to that of the methanol system. At harvesttime, the number of scarred berries per cluster had been reduced for thegrapes treated with Treatments 2 and 3.

The thinning treatments were evaluated following berry set(approximately 2 weeks after bloom). Berry set is a measurement of theachievement of thinning. This is determined by measuring the length andnumber of berries of the upper shoulder of bunches (berry number per cmshoulder length) and the berry set calculated as the berry number per cmshoulder length.

Treatment Berry set Control 4.64 Treatment 1 3.94 Treatment 2 3.95Treatment 3 3.41

With lower numbers to be preferred, Treatment 3 provided the bestresults; Treatments 1 and 2 were similar whilst all three Treatmentswere superior to the Control.

The grapes were harvested at maturity to compare berry weight, lengthand displacement.

Treatment Weight (g) Length (in) Displacement (ml) Control 1.69 0.6021.52 Treatment 1 3.54 0.853 3.23 Treatment 2 3.59 0.857 3.25 Treatment 33.58 0.871 3.27

Each of the Treatments 1, 2 and 3 gave significantly larger berries thanthe Control as shown by average weight, length and displacement.Treatment 2 and 3 gave slightly larger berries than Treatment 1.Treatment 3 gave berries which were longer and of larger volume thanTreatment 2. With all the Treatments having the same level ofGibberellin A-3, the improvements in berry quality can be related to thereplacement of the methanol with the lipophilic solvent.

Example 4

Further laboratory work was undertaken to obtain homogeneouscompositions, the following being examples of such:

Composition A B C D AT 1214 6 5 6 7.5 Butyl Diglysolv 2.8 8.5 11 11Butyl Glysolv 0.9 Ecoteric T-80 4 5 4 4 Esterol 123 55 55 55 55 Esterol244 9.2 10.5 9 9 Ethanol 0.3 Ethyl Diglysolv 6.4 Gibberellic acid 11 1111 11 Glysolv DPM 0.6 NORAM-O 4 5 4 2.5

Composition D was subjected to stability testing. The standardaccelerated test showed no loss of active after 56 days at 40° C. or 56days at 2° C.

Example 5

In this example a field trial was conducted with Gibberellin A-3 carriedin a lipophilic solvent system.

Compositions Tested Were

Treatment 1 ProGibb 10 Treatment 2 10% Gibberellin A-3 in lipophilicsolvent system. Com- position A from Example 4 was used as thelipophilic solvent system for the Thinning and Composition D fromExample 4 was used as the lipophilic solvent system for the Sizingsprays.

Method

The trials were undertaken at a farm at Redcliffs, Victoria. The producewas mostly table grapes for the export market. Within the field of grapevines, 6 strands were allocated to the experimental product. BothTreatments 1 and 2 were applied using a 1500 liter tank per acre of cropas follows:

Treatment 1 or Urea Application 2 Solution. X-77 Phosphate* Timing Spraytype (ml in tank) (ml in tank) (ml in tank) 40-50% bloom Thinning 1 200150 — 3 days later Thinning 2 200 150 — 4-6 mm berry Sizing 1 500 1502000 size 5 days later Sizing 2 500 150 2000 11 days later Sizing 3 700150 2000 *Urea phosphate is a common fertilizer used in the district andapplied with sizing treatments.

Results

At the time of spraying Sizing 1, the grapes from the new product werevisually slightly larger. This observation was again repeated at thetime of spraying Sizing 2.

The grapes from both treatments were harvested on the same day andassessed. The overall impression was that the experimental grapes hadrun 2-3 days ahead to maturity. This is of significant value for anyfarmer with inclement and thus destructive weather being expected at anytime.

Three or four random bunches (approx. 2 kg) were picked from each plotand were assessed for berry size and density. The impact and hence valueto the consumer comes from the overall size of the larger grapes whichvisually dominate and thus affect the value. With at least 8 berriesfrom each bunch, a total of 40 berries (visual selection) were pickedfrom each trial

Average Weight Average density Treatment (g/berry) (ml/g) 1 5.03 0.93 25.80 0.94

A smaller number of the next larger berries were then assessed

Average Weight Average density Treatment (g/berry) (ml/g) 1 4.99 0.926 25.21 0.935

Conclusion

Table grapes of superior quality, and thus sale value, were apparent by

increasing the size of grapes

achieving grape maturity at an earlier date

obtaining more visually attractive berries

eliminating the undesirable flammable/poisonous carrier

Preferably, the composition is applied to the fruit (eg. grapes) inmultiple steps with time breaks between applications dependent on cropmaturity. The application rate of the gibberellins in the spray solutioncan be around 10 ppm for thinning and 30 ppm for sizing. Typically, theactive ingredient is incorporated in amounts in the range of 4 to 10%weight to volume in the composition. Amounts in the range of 1 to 75 mlof such compositions are typically added to 100 L of water forapplication (1 to 30 ppm gibberellins). Further, typical applicationrates of such formulations are in the range of 1000 L to 2000 L of waterper acre.

Example 6

The following composition was prepared.

Component w/w AT 1214 92.4 Butyl Diglysolv 132 Ecoteric T-80 39.6Esterol 123 620.4 Esterol 244 105.6 GA4/7 132 NORAM-O 26.4

This is a stable clear liquid formulation.

The word ‘comprising’ and forms of the word ‘comprising’ as used in thisdescription and in the claims does not limit the invention claimed toexclude any variants or additions.

Modifications and improvements to the invention will be readily apparentto those skilled in the art. Such modifications and improvements areintended to be within the scope of this invention.

The claims defining the invention are as follows:
 1. A plant growthpromoter composition comprising: (a) not in excess of 20% by weight ofthe total composition of one or more gibberellins; and (b) anessentially non-aqueous solvent system comprising: (i) 30 to 99% byweight of the total composition of one or more lipophilic solvents; (ii)one or more lipophilic alkaline coupling agents which enable thegibberellins to form a lipophilic solvent soluble complex, wherein theamount of lipophilic alkaline coupling agents is more than theequivalent molar amount of gibberellins; (iii) 1 to 50% by weight of thetotal composition of one or more emulsifiers which blend with thelipophilic solvent(s) to form a homogeneous product and enabledispersion of the composition into water for application; and (iv)optionally, not in excess of 15% by weight of the total composition ofone or more viscosity reducing co-solvents.
 2. The plant growth promotercomposition according to claim 1 wherein the gibberellin is gibberellicacid (Gibberellin A-3).
 3. The plant growth promoter compositionaccording to claim 1 wherein the amount of gibberellin(s) is in therange of 1 to 15% by weight of the total composition.
 4. The plantgrowth promoter composition according to claim 3 wherein the amount ofgibberellin(s) is in the range of 4 to 10% by weight of the totalcomposition.
 5. The plant growth promoter composition according to claim1 wherein the lipophilic solvent is one or more esters of vegetableoils.
 6. The plant growth promoter composition according to claim 5wherein the esters of vegetable oils are one or more alkyl esters offatty acids.
 7. The plant growth promoter composition according to claim1 wherein the amount of lipophilic solvent is in the range of from 40 to80% by weight of the total composition.
 8. The plant growth promotercomposition according to claim 1 where in the lipophilic alkalinecoupling agent is selected from the group consisting of quarternaryammonium hydroxides, overbased phenates, overbased sulphonates, aromaticamines, arylalkyl amines, alkylaryl amines, polycyclic amines, fattyamines, fatty imidazolines and mixtures thereof.
 9. The plant growthpromoter composition according to claim 8 wherein the lipophilicalkaline coupling agent is a mixture of dimethylcocoamine andoleylamine.
 10. The plant growth promoter composition according to claim1 wherein the amount of lipophilic alkaline coupling agent is in molarexcess to the amount of gibberellin(s).
 11. The plant growth promotercomposition according to claim 10 wherein the amount of lipophilicalkaline coupling agent is about 30% more than the equivalent molaramount of gibberellin(s).
 12. The plant growth promoter compositionaccording to claim 1 wherein the amount of emulsifier is in the rangefrom 3 to 20% by weight of the total composition.
 13. The plant growthpromoter composition according to claim 1 wherein the viscosity reducingco-solvent is selected from the group consisting of glycol, diglycol,diglycol ether and mixtures thereof.
 14. A method for enhancing theefficacy of at least one gibberellin as a plant growth promotercomprising the step of incorporating gibberellins into an essentiallynon-aqueous solvent system to form a plant growth promoter composition,the solvent system comprising: (i) 30 to 99% by weight of one or morelipophilic solvents; (ii) at least an equivalent molar amount to thegibberellins of one or more lipophilic alkaline coupling agents whichenable the gibberellin(s) to form a lipophilic solvent soluble complex;(iii) 1 to 50% by weight of one or more emulsifiers which blend with thelipophilic solvent(s) to furnish a homogeneous product and enabledispersion of the composition into water for application; and (iv)optionally, not in excess of 15% by weight of one or more viscosityreducing co-solvents; wherein the resultant plant growth promotercomposition may be directly applied to a plant.
 15. The method accordingto claim 14 wherein the gibberellin is gibberellic acid (GibberellinA-3).
 16. The method according to claim 14 wherein the amount ofgibberellin(s) is in the range of 1 to 15% by weight of the totalcomposition.
 17. The method according to claim 16 wherein the amount ofgibberellin(s) is in the range of 4 to 10% by weight of the totalcomposition.
 18. The method according to claim 14 wherein the lipophilicsolvent is one or more esters of vegetable oils.
 19. The methodaccording to claim 18 wherein the esters of vegetable oils are one ormore alkyl esters of fatty acids.
 20. The method according to claim 14wherein the amount of lipophilic solvent is in the range of from 40 to80% by weight of the total composition.
 21. The method according toclaim 14 where in the lipophilic alkaline coupling agent is selectedfrom the group consisting of quarternary ammonium hydroxides, overbasedphenates, overbased sulphonates, aromatic amines, arylalkyl amines,alkylaryl amines, polycyclic amines, fatty amines, fatty imidazolinesand mixtures thereof.
 22. The method according to claim 21 wherein thelipophilic alkaline coupling agent is a mixture of dimethylcocoamine andoleylamine.
 23. The method according to claim 14 wherein the amount oflipophilic alkaline coupling agent is more than the equivalent molaramount of gibberellins.
 24. The method according to claim 23 wherein theamount of lipophilic alkaline coupling agent is 30% more than theequivalent molar excess of gibberellins.
 25. The method according toclaim 14 wherein the amount of emulsifier is in the range from 3 to 20%by weight of the total composition.
 26. The method according to claim 14wherein the viscosity reducing co-solvent is selected from the groupconsisting of glycol, diglycol, diglycol ether and mixtures thereof.